Turkey Lakes Watershed Study reference list: 2017

17-01 Enanga, E.M., N.J. Casson, T.A. Fairweather and I.F. Creed. 2017. Nitrous Oxide and Dinitrogen: The Missing flux in Nitrogen Budgets of Forested Catchments? Environmental Science & Technology doi: 0.1021/acs.est.6b03728

Summary: The denitrification products nitrous oxide (N₂O) and dinitrogen (N₂) represent often unmeasured fluxes that may close the gap between explained nitrogen inputs and outputs in forested watersheds. Improved estimates of soil N₂O and N₂ efflux from forested landscapes may require consideration of topographic controls on N cycling and routing processes. Total N inputs, and total gaseous and dissolved N outputs were sampled in 2 catchments (soil N₂O efflux catchment nitrogen output reduced the discrepancy between nitrogen inputs and outputs and between nitrogen outputs from two catchments with different topographies. Annual nitrogen losses may be underestimated without accounting for denitrification products, especially during summer rainfall events.

17-02 Gibson, J.J., S.J. Birks, D.S. Jeffries and Y. Yi. 2017. Regional trends in evaporation loss and water yield based on stable isotope mass balance of lakes: The Ontario Precambrian Shield surveys. Journal of Hydrology doi: 10.1016/j.jhydrol.2016.11.016

Summary: This study was undertaken to gain a better understanding of hydrology and geochemistry of watersheds in the region in order to better predict acid sensitivity of lakes. Stable isotopes of water, oxygen-18 and deuterium were measured in water samples from 300 lakes in the vicinity of Lake Superior, and also within the TLW. Evaporative isotopic enrichment of lake water was systematic across the regions, and its deviation from the isotopic composition of precipitation was used to estimate the evaporation/inflow to the lakes and runoff (water yield) based on a simple isotope mass balance model. Results suggest that a high proportion of lakes have relatively limited runoff, so basic information on the drainage structure of an area can be valuable for site-specific hydrologic assessments, and critical loads assessment (low runoff systems tend to be less buffered and therefore are more sensitive to acidification. In TLW, isotope-based water yield is comparable in magnitude to hydrometric gauging estimates, although uncertainty related to stratification can be high for individual lakes, but would only be a minor influence on regional survey results.